1. Field of the Invention
The invention relates to a connector provided with a retainer for locking terminal fittings.
2. Description of the Related Art
Japanese Unexamined Utility Model Publication No. 6-58570 discloses a known connector with a housing and a retainer that is mounted on the housing for movement from a partial mounting position to a full locking position. Terminal fittings can be inserted into the housing and partially locked when the retainer is in the partial mounting position. The retainer then is pushed to the full locking position for doubly locking terminal fittings.
The retainer and the housing have means for locking the retainer at the partial locking position and at the full locking position. Specifically, the retainer has a resilient locking piece that extends parallel to the pushing direction of the retainer from the partial locking position to the full locking position. A partial locking projection is formed at a leading end of the resilient locking piece and a full locking projection is formed more toward the base end of the resilient locking piece than the partial locking projection. The housing is formed with one fastening projection common to both partial and full locking projections.
The fastening projection is held between the partial locking projection and the full locking projection when the retainer is in the partial locking position. The retainer then can be pushed to the full locking position. The pushing force causes the full locking projection to deform away from the fastening projection and then to move over the fastening projection. Thus, the resilient locking piece engages the fastening projection to prevent a returning movement of the retainer toward the partial locking position.
A jig can be used to return the retainer from the full locking position to the partial locking position so that the terminal fitting can be withdrawn from the housing. As a result, the resilient locking piece deforms and the full locking projection disengages from the fastening projection. The resilient locking piece is restored resiliently as the full locking projection moves over the fastening projection. As a result, the fastening projection is held between the full and partial locking projections and in the partial locking position.
An excessively large force must be exerted on the retainer during the retainer returning operation because of the need to disengage the full locking projection from the fastening projection and the need to deform the resilient locking piece against its resilient force. There is a possibility that the large force required to move the retainer back to the partial locking position will inadvertently drive the partial locking projection over the fastening projection. Thus, the retainer may come out of the housing.
The invention was developed in view of the above problem and an object thereof is to prevent a retainer from coming out of a housing when the retainer is moved from a full locking position to a partial locking position.
The invention relates to a connector with a housing and a retainer that is moveable between first and second positions on the housing. At least one terminal fitting is inserted into the housing when the retainer is at the first position. The retainer then can be pushed to the second position to lock the terminal fitting in the housing. At least one resilient locking piece is cantilevered on the retainer and extends substantially in the pushing direction of the retainer from the first position to the second position. A first projection is near the free end of the resilient locking piece and a second projection is closer to the base end of the resilient locking piece. A fastening projection is formed in the housing and causes the resilient locking piece to deflect as the retainer is moved between the first and second positions. However, the resilient locking piece is restored resiliently when the retainer is in either of the first or second positions. Thus, the fastening projection engages the first projection when the retainer is in the first position and engages the second projection when the retainer is in the second position. A preventing means is provided for limiting deflection of the resilient locking piece when the first projection is engaged with the fastening projection, and hence prevents the retainer from disengaging from the housing in response to forces exerted for moving the retainer from the second position to the first position.
The fastening projection is engaged between the first and second projections to prevent loose movement of the retainer from the first position.
The second projection preferably is engageable with the free end side fastening projection to restrict the retainer from making a return movement toward the first position.
The preventing means prevents the free end of the resilient locking piece from displacing in response to forces in a direction for detaching the retainer from the housing. Thus, the resilient locking piece effectively is supported at both ends instead of being supported only at the base end. Accordingly, an apparent resilient force of the resilient locking piece is high, and deformation of the resilient locking piece is more difficult. The preventing means also prevents the first projection from moving over the fastening projection as the resilient locking piece is deformed resiliently. As a result, the retainer can be held at the first position.
Preferably, the second projection projects from the resilient locking piece less than the first projection.
The resilient locking piece is supported only at one end and is angularly displaceable. Thus, if the projecting distances of the first and second projections are equal, a degree of inclination of the resilient locking piece is larger when the first projection (closer to the free end) moves over the fastening projection than when the second projection (more distant from the free end) moves over the fastening projection. Therefore a larger force is required to move the retainer from the second position to the first position, and a design with equal projecting distances of the first and second projections is not preferable in view of operability.
In this respect, the projecting distance of the second projection is smaller than the projecting distance of the first projection according to the preferred embodiment. Thus, improved operability can be realized by reducing the force required to move the retainer between the second position and the first position while still preventing detachment of the retainer from the housing.
The free ends of the resilient locking pieces preferably are brought substantially into contact to restrict displacements of the free ends.
Two resilient locking pieces and two fastening projections preferably are provided and are substantially symmetrical. Thus, the free ends of the resilient locking pieces contact each other to restrict displacements of the free ends when the resilient locking pieces try to deform in directions that would disengage the first projections from the fastening projections with the retainer held at the first position.
The preventing means preferably is formed only by the resilient locking piece of the retainer, and the housing needs no preventing means. Thus, the housing has a simpler shape.
The second projections preferably are substantially symmetrically to each other.
The projecting distance of one of the second projections preferably is different than the projecting distance of the other of the second projections.
The retainer preferably is inserted into the housing at an angle to the inserting direction of the terminal fitting into the housing.
These and other objects, features and advantages of the present invention will become more apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings. It should be understood that even though embodiments are separately described, single features thereof may be combined to additional embodiments.